Weather Forecast

Over 60 ranchers and livestock managers from Colorado and Nebraska attended the Ranchers Field Day near Wray Tuesday, June 11. Pat Reece, owner of Prairie & Montane Enterprises and University of Nebraska-Lincoln professor emeritus led the field day.

The group looked at sand pastures in the morning and loamy rangeland in the afternoon. Discussions focused on drought effects on rangeland vegetation and how grazing management decisions can minimize or exacerbate those effects.

Severe drought stress in 2012 and this year has measurably reduced the carrying capacity of rangeland in this region. Density, weight and height of needle-and-thread tillers are much lower compared to healthy predrought plants. Prairie sandreed, a warm-season tallgrass on sandhills rangeland, was also shorter and often less abundant.

A striking feature on sand and loamy pastures was the widespread death of blue grama. Areas with gray sod and only an occasional green tiller indicate that most of the blue grama plants have died. Plants will not grow from crowns or roots under the gray blue-grama sod.

Grazing plans should always be designed to minimize the amount of bare ground in pastures. It is especially critical during drought years because of the need to reduce soil temperature extremes and to optimize infiltration. Ground cover includes living and dead plants and litter, Reece explained. Surface soil temperatures can easily exceed 120 degrees on hot days like ranchers saw last summer and in recent days.

“Imagine what that does to rangeland plants,” said Reece.

Bone-dry soil pits and the common occurrence of rolled grass leaves correspond to 50 percent cumulative precipitation deficits in this region. Once the ground gets this dry, water from the next rainfall will be tightly held by the soil particles, reducing its availability to plants.

Pat Reece discusses the importance of looking at the ground to determine plant health and density.

After lunch, the group went through the Cumulative Forage Reduction Index Reece and others have developed. This worksheet tracks current precipitation against the long-term average. The resulting deficit, or surplus, is multiplied by the expected plant growth in that month.

One can then see what forage shortage or surplus to expect in the months ahead based on current precipitation. It takes the mystery out of knowing how much grass to expect in the coming months, so stocking decisions can be made before running out of grass.

Contrary to popular belief, plants do not have the ability for “compensatory gain” like animals. Every plant has a unique set of environmental conditions for rapid plant growth. Once those are past, the plant cannot grow to anything near its full potential.

In the afternoon, the fact that 45 people endured the over-100-degree heat and a blast-furnace wind to look at the hard ground site is a testament to the value of the information shared that day.

The take-home message of the day was, “Do not combine overgrazing with drought stress on rangelands,” Leave adequate standing herbage” and “Contact a local NRCS range specialist to get help evaluating rangeland and determining a moderate stocking rate.”